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A Study On Bias And Selection Bias

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Bias Although prospective cohort studies have fewer potential sources of bias and confounding than retrospective studies, the study is still vulnerable to bias. The study is vulnerable to selection bias. Selection bias occurs in a cohort study when the loss to follow-up is related to both the exposure and outcome of interest. Loss to follow-up can arise in the study, if subjects can no longer be located or when they no longer want to participate in a study. Loss to follow-up is problematic since it can reduce the power of the study to detect associations that are truly present, and it can bias the study results. Individuals in the study can be lost due to many reasons such as personal choice to opt out of the study, death, or change in geographic location. Loss to follow-up did occurred in this study. Of the 37,500 individuals, 2,700 participants were lost during follow-up. Due to loss to follow, it can bias the results by causing the true measure of association to be either overestimated or underestimated. To reduce loss to follow, is to obtain high participation rate. High participation rates is not always feasible but most epidemiologists are satisfy with participation rates greater than 80%. The participation rate of the study is 92.8%. Although the rate is higher than 80%, it is still important to consider how this bias impacts the outcome. In addition, the study is vulnerable to information bias. Information bias is an error that is due to systematic differences in

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